Hope someone can give a bit of input on this as I am at a loss on what is going on and how to fix it...

All that I can attribute this to is a week or so ago I lowered a moderately heavy (for me) push jerk (100Kg) a bit too hard into the rack position, later that session I tried to do some back squats. To just rack the bar causes pain in my lower back/ glute area, mainly on the left hand side.

I am able to still snatch, snatch deadlift and clean with no real discomfort but when I try and put a bar any heavier than 70Kg on my back it hurts.

My right hip responds well to Single Leg Deadlifts with a DB. I feel stupid doing them but it seems to alleviate hip and lower back pain on my right side. On the left side, I just feel off balance but ehh. The Reverse Hypers tend to be my go to exercise besides a lot of hanging and support swings on Rings and PB. However, they aren't regular swings but pikey swings that focus on opening up my lower back. Straddle ring swings do wonders as do Ring Hip circles. Either that or just get the hip adjusted.

I hurt my back twice in 2010 when I was trying to get back under the bar after about 6 mo without doing 531. As well coaching and working out at the gym. Injured it pretty soon under the bar and then about a cycle or too later which I think had more to do with a spotting injury or training event injury than the bar.

That being said, it always seems I have to work on my hips and lower back or it starts creeping up on me. Maybe because I had a bad back hyperextension about 10 years ago on trampoline. No idea. The hip was always a problem from playing right handed sports and only got worse as I got older so I have to watch it or it'll start acting up eventually when vault or tumbling come to play.

If it's a lumbar disc issue (and most of us probably have them), the reverse hyper is a great exercise, as it simultaneously strengthens the stablizers and glutes, which protect the back, and puts the back in traction which alleviates the pressure. I'd also look into where your hip mobility is limited, as tightness below will pull the back into flexion when under load, which is just about the worst thing in the world for a spine. I suffer the same symptoms, but our issues could well be different. Still, the stretches that are the most important for me are hip flexor stretches (which often alleviate the pain right away) and hamstring stretches (the latter using a belt around my foot with my back flat on the floor). Your mileage may vary. Let us know how it goes.